Allow to unset fields

Author: Daniel Fariña Hernández

src/AutopilotContact.php

@@ -200,11 +200,6 @@ public function toRequest($prependKey = true)
 
         /** @var AutopilotField $field */
         foreach($this->fields as $field) {
-            //TODO: how do you "unset" fields with Autopilot? Their API doesn't say anything about it
-            if ($field->getValue() === null) {
-                continue;
-            }
-
             if (! $field->isReserved()) {
                 $result['custom'][$field->formatName()] = $field->getValue();
             } else {
@@ -246,4 +241,4 @@ function jsonSerialize()
     {
         return $this->toArray();
     }
-}
+}

src/AutopilotField.php

@@ -229,7 +229,7 @@ public function setValue($value)
         }
 
         // type of field is set in the constructor
-        if ($this->getType() !== $type) {
+        if (($this->getType() !== $type) && !is_null($value)) {
             throw AutopilotException::typeMismatch($this->getType(), $type);
         }